Photonics is an emerging technology viewed by many as the future direction of optical signal processing and ultrafast optical computing. Photonics is generally a technology where photons rather than electrons are used to carry informational signals.
Nonlinear optical effects of photonic media play an important role in photonics. Nonlinear optics refers to the nonlinear relationship between the response of the material and the intensity of infinite light. An important manifestation of the effect of nonlinear optics is the dependence of the refractive index on the intensity of light. Nonlinear optical effects are important in photonics because they provide means to produce optical switching (optically induced switching of a device from a low optical transmission state to a high optical transmission state) and optical bistability (behavior of a device whereby the device exhibits two optical absorptions within a given range of input values). Optical switching and optical bistability are functions needed for optical logic and optical memory operation.
Conjugated organic polymers are considered an important class of optical material because they have demonstrated large, non-resonant (non-absorptive), optical nonlinearity with ultra fast response time in the sub-pico seconds regime, ("Nonlinear Optical and Electroactive Polymers" Edr's, P. N. Prasad and D. R. Ulrich, Plenum Press, N.Y. 1988). These polymers in their pure state, however, have generally not been found to form good photonic media because they typically exhibit high optical losses. For example, optical film made of pure poly-p-phenylene vinylene, a conjugated organic polymer, exhibits refractive index inhomogeneities (i.e. the refractive index varies from domain to domain) and degraded optical quality.
Many glasses, including silica glass, are also considered an important class of optical material in that they form excellent photonic media because of extremely low optical losses. A major problem with many glasses is that their optical nonlinear coefficient (the quantitative representation of the strength of the nonlinear optical effects; X.sup.( 3) -- third order nonlinear coefficient) is extremely low. Optical switching in silica wave guides (devices which channel optical waves formed in silica) has been observed; however, long interaction lengths are necessary to compensate for the extremely low optical nonlinearity.
Therefore, currently there exists a need for a material having high, nonlinear optical coefficients, high optical quality (scattering and absorption losses within the material is small).
Accordingly, an overall object of the invention is to provide a nonlinear, high optical quality material.
A more particular object of this invention to provide a composite material capable of being formed into nonlinear, high optical quality wave guides with low optical losses.
A further object of the invention is to provide a material which exhibits good mechanical strength, and possess environmental and thermal stability.
Still another object is to provide a material having the above qualities, which can be incorporated into integrated optical device structures, in the form of optical fibers and optical wave guides with high optical through-puts; and into channel wave guides (structures having a plurality of channels that propagate light).
Another object of the invention is to provide a method of making the composite material, having the above qualities, which will provide enhanced protection for the active element in the environment.